Heat exchanger for the condensation or vaporization of fluids



United States Patent.

Inventors Rudolf Thomae,

Heidelberg, and Gerd Schwarzkopf, Walldorf, Germany Appl. No. 775,732 Filed Nov. 14, 1968 Patented Nov. 10, 1970 Assignee J- Reiert Gmbll a corporation of Germany Priority June 7, 1968 Germany 1,751,489 and A 29,924

HEAT EXCHANGER FOR THE CONDENSATION 0R VAPORIZATION 0F FLUIDS l1 Clalms, 7 Drawing Figs.

US. Cl. 165/104, 165/105, 165/117 Int. Cl. r. F28d 13/00 Field of Search 165/104,

References Cited Primary Examiner-Charles Sukalo Attorneys-Richard C. Strickler, Robert H. Bachman, Donald R. Motsko and Thomas P. ODay ABSTRACT: This application discloses a heat exchanger for condensing or vaporizing fluids which contains a bell-shaped heat exchange component mounted in a tubular container, a plurality of tubes for conveying a first heat exchange fluid, with the tubes being mounted in the bell-shaped heat exchange component, a porous, metallic material comprising a plurality of metallic particles heat conductively connected to each other and to the outside walls of the tubes and to the inside walls of the bell-shaped component, the porous material being within the bell-shaped component and conveying a second heat exchange fluid in heat exchange relationship with the first heat exchange fluid.

Patented Nov. 10, 1970 Sheet I ATTORNEY Sheet INVENTORS RUDOLF THOMAE GERD SCHWARZKOPF ATTORNEY 3 Patented 1 Nov. 10, 1970 sheet 3 as INVENTORS RUDOLF THOMAE GERD SCHWARZKOPF ATTORNEY Heat exchangers, for the condensation or vaporization of fluids are well known. Conventionally theyhave a tubular storage container and a heat exchange part mounted within this storage container.

The condenser is customarily constructed in such a manner that smooth or finned tubes extend in the longitudinal direction through the storage container, through which tubes the cooling agent flows and on whose outside walls the gaseous fluid or refrigerant which is introduced into the container can condense within the storage container. In the lower part of the storage container, the condensed fluid accumulates and is usually subcooled by several additional tubes conducting cooling agent.

In evaporators'for the direct vaporization of liquids, the type of construction is similar to that of condensers; however, in this case the vaporization is chiefly accomplished in the tubes which frequently in addition exhibit an inner finning.

Removable covers at the end of the storage tank contain fluid return chambers.

Heat exchangers of these types are always relatively large, heavy andQtherelore, costly and expensive to manufacture, even with the best known method ofconstruction.

Considerably higher heat transfer coefficient values are achieved by a heat exchanger according to the present invention than has'been previously possible with the conventional methods of construction. It is, therefore, possible to achieve considerably smaller dimensions with the heat exchanger proposed according to the present invention and correspondingly also considerably lower weights. This is advantageous both in the constructive respect with regard to the assembly size, and above all things also with regard to the manufacturing costs.

Heat exchangers according to the present invention, for the condensation or vaporization of fluids, contain a tubular storagetankand heat exchange parts arranged in this storage tank. The invention resides in the fact that the heat exchange component is in the form of a longitudinally-extendedbell and has tubes proceeding in a longitudinal direction for a cooling or heating agent, which tubes are embedded in a porous material.

The porous material comprises a plurality of metallic particles, preferably of a spherical or cylindrical shape. The particles are connected heat conductivcly with one another as well as with the outside walls of the tubes and with the inner walls of the bell. Preferably the heat exchange part shaped in the form of a longitudinally extended bell exhibits a hollow space lying above the porous, material. The porous material is separated from the hollow space lying above by a closemeshed metal lattice, preferably expanded metal, which is connected with a U-shaped longitudinal stiffener open to the top of the same lattice material. One or several, preferably vertically directed, inlet tubes discharge into the hollow zone of the bell-shaped heat exchange part in which circular metal discs are arranged lying coaxiallyopposite the inlet tube opening on the close-meshed metal lattice, which at least exhibit the diameter of the tube opening lying above. 7

Preferably additional heat exchange tubes are arranged below the bellshaped heat exchange component in the storage tank, which in the case of the evaporator lie in a groove-shaped plate and are connected heat conductively therewith. V

If it is necessary to arrange particularly large heat transfer capacities in the smallest space, more than one bell-shaped heat exchange component can be arranged in one storage tube.

The tubes passing through the end walls of the storage tank for the heating or cooling agent project at least 3 mm. from the outer end wall plane. By this arrangement of the tube ends, it is possible to apply an elastic sealing plate on the back walls, which contains appropriate openings for the tubes. A further sealing plate was applied below the cover. In this manner, it is possible to form the return chambers as framelike loose elements, which then are merely attached between the sealing plates on the endwall and the sealing plate below the cover by clamping. This construction of the return chambers permits the very rapid changeover from one tube flow path to another, as, for example, can be the case if a heat exchanger must be operated with different amounts of water than previously. A further advantage of these loose framelike return chambers is that they can be manufactured from a suitable plastic. In such a case, all side walls of the water chambers consist of nonmetallic materials, which is extremely advantageous from a corrosion basis.

Various model examples of heat exchangers according to the invention are depicted in the drawings which are partly schematic and partly in section.

FIG. 1 shows a heat exchanger fashioned as a water cooled condenser on one side of which the individual parts of the water chambers are depicted separated from one another.

FIG. 2 shows a section along the section line 2-2 of FIG. 1.

FIG. 3 shows the end view of the heat exchanger of FIG. 1, with inserted framelike return chamber.

FIG. 4 shows a heat exchange component fashioned in the shape of a longitudinally extended bell according to the present invention, partially in cutaway.

FIG. 5 shows a heat exchanger according to the invention, which is fashioned as an evaporator for the cooling of liquid media.

FIG. 6 shows a section of the heat exchanger of FIG. 5 along the section line 6-6 of FIG. 5.

FIG. 7 shows a sectional view through a heat exchanger according to the present invention, in which three bell-shaped heat exchanger components are arranged.

Considering use as a condenser (cf. FIGS. 1, 2, and 3), a heat exchange component 2 in the form of a longitudinally extended bell is arranged in a storage container 1. The storage container is sealed on both ends by end plates 3 which are found several cm. from the outer edge of the storage container and within the container. These end plates are penetrated by the tubes 2a of the bell-shaped heat exchange component 2, as well as by additional heat exchange tubes 7 in such manner that the tube ends project at least 3 mm. from the outer end wall plane. An inlet tube 4 opens into the upper part of the storage container l'and also penetrates the heat exchange component 2,and at the penetration position is connected tightly with the storage container. In place of one inlet tube 4, also several 4a, 4b can also be present, which then are connected by a common connection tube 40. Close to the end of the storage container I there is a dip tube 5 with a shutoff valve 6, which servesas an outlet for condensed refrigerant.

The tubes 7 serve for subcooling of condensed refrigerant. On the outside, the storage container 1 is sealed by the end cover 11, which is sealed on the edge of the storage container by means of an elastic sealing disc 10. On the outside of the inner plate 3, a further elastic sealing disc 8 is present which contains openings through which the ends of the tubes 2a and 7 can pass. Between the seals 8 and 10 a framelike part is clamped which forms the return chamber for the cooling agent. The pressure for the clamping and the scaling is achieved by spacer bolts 12 and nuts 13. The spacer bolts 12 are surrounded by elastic sealing housings 12a.

In operation, gaseous refrigerant flows into the bell-shaped heat exchange part at 4 leaves this at the lower side in the form of condensate, which flows down from the bottom of the entire length of the heat exchange component as from a sprinkler.

In the lower part of the storage container 1, the condensate is accumulated, subcooled by the tubes 7 and leaves the condenser through the dip tube 5 and the valve 6. The cooling agent flows through the inlet connection 14 into one of the .outer seal covers, flows first through the subcooling tubes 7 through the connection 15. Bent feet 16 serve for mounting of the condenser.

If the heat exchanger according to the invention is used as an evaporator for the cooling of liquid media (cf. FIGS. 5 and 6), it is essentially fashioned exactly in such manner as has been described previously. The inlet tube 4 was merely replaced by a plurality of so-called injection tubes 21 which exhibit considerably smaller diameter than the tube 4 and which produce the connection between a refrigerant distributor 22 which is installed with a regulator valve 23 and allows flow into the hollow space of the bell-shaped heat exchange part. The penetration positions of the tubes 2] through the component 2 are sealed tight in a manner similar to the tube 4. In the drawing, the valve 23 is a thermostatic expansion valve with external pressure equalization in which the pressure equalization line is designated by 24 and the capillary tube for the sensing bulb by 25. The tubes 7 in the case of the evaporator no longer serve for the subcooling of liquid refrigerant but rather for the superheating of refrigerant vapors. They are preferably connected heat conductively with a troughlike plate 30 in order to vaporize the refrigerant or refrigerant-oil mixture still emerging in liquid form from the lower side of the bell-shaped heat exchanger 2. The discharge from the evaporator for the vaporized refrigerant is accomplished by a tube line 31 installed at the bottom of the storage container 1. Both the storage container and the connection site of the expansion valve sensing bulb are suitably surrounded by an insulation as is designated by 26 and 27.

The heat exchange part (cf. FIG. 4) is fashioned in the form of a longitudinally extended bell and consists of a U-shaped jacket plate 2)) open to the bottom, which is sealed on both ends by sealing covers 20. These sealing covers are provided with openings through which tubes 2a pass through. These tubes 2a go through the entire heat exchanger and at both ends stand out a predetermined distance above the sealing cover 2c. In the region of the tubes the heat exchange part is packed with particles of a high heat conducting metal, which are connected heat conductively with one another, with the outside walls of the tubes 20 and with the inside of the jacket plate 211 wherever it contacts the particles so that the resulting porous matrix is stronger. The form and diameter of the metal particles (spherical or cylindrical), the distance of the tubes 2a from one another and the diameter of the tubes 2a are of great influence on the quality of the heat exchange part and must be determined optimally from case to case. Below the region of the bell-shaped heat exchange part penetrated by the inlet tube 4 is found a hollow space. This hollow space is sealed off by a flat metal lattice 18 on which a U-shaped metal lattice 19 open to above is mounted centrally. Metal discs 20 are attached to the metal lattice below the discharge of the tube connections designated here by 4, which provide for a better distribution of the entering medium.

In order to save space, also several like heat exchange parts 2, as shown in FIG. 7, can be installed in a common storage container 1. In the case ofa condenser, it may be desirable to add an additional liquid storage container la, which is connected with the storage tube 1 by a tube 28. In this case it is suitable to attach the storage container 1 above the additional storage container 1a on supports 29. The remaining reference numbers agree with those of FIGS. 1-3 since it is again a matter ofa condenser in the example of FIG. 7.

This invention may be embodied in other forms or carried out in other ways without departing from the spirit or essential characteristics thereof, The present embodiment is therefore to be considered as in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency are intended to be embraced therein.

We claim:

I. A heat exchanger for condensing or vaporizing fluids which comprises: a bell-shaped heat exchange component; a plurality of tubes for conve ing a first heat exchan e fluid mounted within said heat exc ange component; a tubu ar container mounting said bell-shaped heat exchange component, wherein said component extends in the longitudinal direction and wherein said tubes extend in the longitudinal direction; a porous, metallic material within said component embedding said tubes for conveying a second heat exchange fluid in heat exchange relationship with said first heat exchange fluid, wherein said porous, metallic material comprises a plurality of metallic particles heat conductively connected to each other, to the outside walls of said tubes and to the inside walls of said component.

2. A heat exchanger according to claim I wherein said particles are cylindrical.

3. A heat exchanger according to claim I including a hollow space above said porous material.

4. A heat exchanger according to claim 3 wherein said porous material is separated from the hollow space by a closemeshed, metal lattice.

5. A heat exchanger according to claim 4 including a U- shaped longitudinal stiffener, open to the top made of said close-meshed, metal lattice material.

6. A heat exchanger according to claim 4 including at least one inlet tube for discharging fluid into said hollow space and a circular metal disc opposite each said inlet tube on said lattice having at least the diameter of the inlet tube.

7. A heat exchanger according to claim 6 including at least one additional heat exchange tube lying below said bellshaped component and lying within a troughlike plate connected heat conductively therewith wherein said additional heat exchange tube is in fixed spaced relationship to said plurality of tubes.

8. A heat exchanger according to claim 1 including a plurality of bell-shaped, heat exchange components mounted in said tubular container in fixed, spaced relationship to one another.

9. A heat exchanger according to claim 1 wherein said tubes extend beyond the end walls of said tubular container for a distance of at least 3 mm.

10. A heat exchanger according to claim 9 wherein the end wall of said tubular container is covered with an elastic sealing plate which is penetrated by said tubes.

11. A heat exchanger according to claim 10 including frame shaped, loose return chambers mounted adjacent the end wall of said container. 

